Harry Potter and the Hide Story
Time Limit: 10000/5000 MS (Java/Others) Memory Limit: 65536/65536 K (Java/Others)
Total Submission(s): 2809 Accepted Submission(s): 715
Problem Description
iSea is tired of writing the story of Harry Potter, so, lucky you, solving the following problem is enough.

Input
The first line contains a single integer T, indicating the number of test cases.
Each test case contains two integers, N and K.
Technical Specification
1. 1 <= T <= 500
2. 1 <= K <= 1 000 000 000 000 00
3. 1 <= N <= 1 000 000 000 000 000 000
Each test case contains two integers, N and K.
Technical Specification
1. 1 <= T <= 500
2. 1 <= K <= 1 000 000 000 000 00
3. 1 <= N <= 1 000 000 000 000 000 000
Output
For
each test case, output the case number first, then the answer, if the
answer is bigger than 9 223 372 036 854 775 807, output “inf” (without
quote).
each test case, output the case number first, then the answer, if the
answer is bigger than 9 223 372 036 854 775 807, output “inf” (without
quote).
Sample Input
2
2 2
10 10
Sample Output
Case 1: 1
Case 2: 2
思路:素数分解;
当K = 1的时候肯定输出inf;我们将n分解成素数的乘积,那么我们需要找m!分解后含有这些素数的个数cnt[pi],那么最高次就是min(cnt[pi]/cnt1[pi]);cnt1[pi]为n中pi的个数。
1 #include<stdio.h>
2 #include<algorithm>
3 #include<iostream>
4 #include<queue>
5 #include<set>
6 #include<math.h>
7 #include<string.h>
8 using namespace std;
9 typedef unsigned long long LL;
10 bool prime[10000015];
11 LL ans[1000000];
12 LL prime_table[10000];
13 LL pr_cnt[10000];
14 LL pr_cn[10000];
15 LL slove(LL n,LL m,int cn);
16 int main(void)
17 {
18 int T;
19 scanf("%d",&T);
20 int i,j;
21 for(i = 2; i < 10000; i++)
22 {
23 if(!prime[i])
24 {
25 for(j = i; (i*j) <= 10000010; j++)
26 {
27 prime[i*j] = true;
28 }
29 }
30 }
31 int cn = 0;
32 for(i = 2; i < 10000010; i++)
33 if(!prime[i])ans[cn++] = i;
34 int __ca = 0;
35 while(T--)
36 {
37 LL n,m;
38 __ca++;
39 scanf("%llu %llu",&m,&n);
40 printf("Case %d: ",__ca);
41 if(n == 1)
42 printf("inf\n");
43 else
44 {
45 printf("%llu\n",slove(n,m,cn));
46 }
47 }
48 return 0;
49 }
50 LL slove(LL n,LL m,int cn)
51 {
52 int bn = 0;
53 int f = 0;
54 bool flag = false ;
55 memset(pr_cnt,0,sizeof(pr_cnt));
56 memset(pr_cn,0,sizeof(pr_cn));
57 while(n>1)
58 {
59 while(n%ans[f]==0)
60 {
61 if(!flag)
62 {
63 flag = true;
64 bn++;
65 prime_table[bn] = ans[f];
66 }
67 pr_cnt[bn]++;
68 n/=ans[f];
69 }
70 f++;
71 flag = false;
72 if((LL)ans[f]*(LL)ans[f] > n)
73 break;
74 }
75 if(n > 1)
76 {
77 bn++;
78 prime_table[bn] = n;
79 pr_cnt[bn]++;
80 }//printf("%d\n",n);
81 LL maxx = -1;
82 for(int i = 1; i <= bn; i++)
83 { //printf("%llu\n",prime_table[i]);
84 LL v = m;
85 while(v)
86 {
87 v/=(LL)prime_table[i];
88 pr_cn[i]+=v;
89 }
90 if(maxx == -1)
91 {
92 maxx = (LL)pr_cn[i]/(LL)pr_cnt[i];
93 }
94 else
95 maxx = min((LL)pr_cn[i]/(LL)pr_cnt[i],maxx);
96 }
97 return maxx;
98 }